An audit of pressure sores caused by intermittent compression devices used to prevent venous thromboembolism.
Abstract: When intermittent compression devices (ICDs) are used to prevent venous thromboembolism (VTE) they can cause pressure sores in a selected group of women, undergoing long operations. A prospective audit pre and post intervention showed a reduced risk with an alternative device, without increasing the risk of VTE.

KEYWORDS Pressure sores / Intermittent compression device / Prevention / Venous thromboembolism / DVT
Article Type: Report
Subject: Bedsores (Prevention)
Bedsores (Diagnosis)
Bedsores (Care and treatment)
Bedsores (Research)
Surgery, Plastic (Research)
Surgery, Plastic (Health aspects)
Thromboembolism (Prevention)
Thromboembolism (Diagnosis)
Thromboembolism (Care and treatment)
Thromboembolism (Research)
Authors: Skillman, Joanna
Thomas, Sunil
Pub Date: 12/01/2011
Publication: Name: Journal of Perioperative Practice Publisher: Association for Perioperative Practice Audience: Academic Format: Magazine/Journal Subject: Health; Health care industry Copyright: COPYRIGHT 2011 Association for Perioperative Practice ISSN: 1750-4589
Issue: Date: Dec, 2011 Source Volume: 21 Source Issue: 12
Topic: Event Code: 310 Science & research
Product: Product Code: 8000418 Cosmetic Surgery NAICS Code: 62 Health Care and Social Assistance
Geographic: Geographic Scope: United Kingdom Geographic Code: 4EUUK United Kingdom
Accession Number: 274700153
Full Text: Retrospective and prospective audits were carried out after plastic surgery patients developed ankle pressures sores postoperatively. Changing the ICD reduced the risk of pressure sores without increasing the apparent risk of venous thromboembolism. Organisations should be made aware of the potential limitations of some ICDs, and avoid a prominent inflation tube exerting undue pressure, particularly over bony prominences like the lateral malleolus in operations lasting more than six hours.

Background

Anecdotal reports of Grade I pressure sores following use of ICDs were reported in our unit. This iatrogenic injury caused severe pain, redness and paraesthesia around the lateral ankle in several women who had undergone lengthy operations for breast reconstruction after mastectomy. In some cases the pain lasted for several days and in one case the paraesthesia took three months to resolve.

Intermittent compression devices are well established for venous thromboembolism prophylaxis in surgical specialities (Eppsteiner et al 2010). They diminish venous stasis by compressing the leg intermittently and also stimulate endogenous fibrinolysis (Comerota et al 1997). Their major advantage is that they reduce the risk of bleeding complications compared with pharmacological methods of prophylaxis (Eppsteiner et al 2010, Freedman et al 2000, Urbankova et al 2005). This is especially useful in plastic surgery, where it is important to avoid haematoma. In particular, free tissue transfer is a lengthy surgical procedure (6 21 hours in this series) where tissue is transferred from one area of the body to another and the blood vessels reconnected by microanastomosis. Any compression of this anastomosis, for example by haematoma, can cause complete failure of the reconstruction. It is common practice to apply ICDs to both lower limbs at the start of the surgery and leave them in place for the first 24 hours postoperatively. In addition, in our unit, patients are given low molecular weight heparin pre and post operatively.

The objective of the audit was to elucidate the cause of the pressure areas, to identify which factors put the patient at risk and to prevent further incidence of iatrogenic injury. The audit took place in a tertiary referral plastic surgery unit in women undergoing free flap breast reconstruction. These patients were selected as they were at higher risk of pressure sores and VTE due to lengthy operative times (6-21 hours).

Assessment of problems

Clinical staff caring for the patients post operatively identified the problem. It was unexpected that severe pain in the ankles should occur as this was outside the operative site in all cases. The cause of the pain was investigated. The ICDs in use were examined: they were constructed with expandable pockets, which compressed the calf intermittently when inflated with air. The prominent plastic inflation tubing entered the inside of the calf cuff adjacent to the ankle. When the cuff inflated, the hard, uncushioned edge of the tube was pushed firmly against the leg. The repeated pressure of this tube had caused the symptoms of skin discolouration and paraesthesia in a small number of our patients. Once the iatrogenic cause was identified, we wanted to identify whether there had been any other similar problems caused by ICD pumps in other patients.

A retrospective audit of ICD use was undertaken in our department. Ten consecutive women who had had free flap breast reconstruction operations after mastectomy were selected. In addition to the index case which highlighted this potential problem, another woman (1/10) had complained of severe pain in both ankles post operatively. As the symptoms did not seem to be an isolated event, a prospective audit was planned.

Prospective audit

The primary aim of the prospective audit was to identify any further incidence of ankle or leg symptoms in women having free flap breast reconstruction, and to clarify whether this problem was recurrent or a solitary event. The secondary aims were to identify risk factors for development of pressure sores in this group, to allow us to develop strategies for prevention.

A prospective audit of 20 consecutive women undergoing free flap breast reconstruction was undertaken. The patients' height, weight, age and operative details were recorded. Postoperatively each woman completed a visual analogue scale to estimate leg pain and paraesthesia. Leg examination was performed postoperatively and 48 hours later. Symptoms that the women experienced were correlated with operative time, height, weight and body mass index.

Results of assessment/measurement

In our prospective audit, three patients had severe pain, and one had associated paraesthesia. These three patients had a mean body mass index (BMI) of 22.6 and mean height of 160cm (Figure 1); they were shorter and with a lower BMI than the women in the cohort who did not develop pressure sores. The mean for whole group was BMI 26.0 and height 170cm. Women who developed pressure sores and symptoms had an operative time longer than eight hours and two of the three women had operative times exceeding 10 hours. These operative times were similar to the whole cohort who had a mean operating time of 9 hours 15 mins (range 6 hours to 21 hours). Therefore, operative time was not closely correlated with the formation of pressure sores.

[GRAPHIC OMITTED]

In the symptomatic, shorter, slimmer women, the firm tubing of the ICD pump tended to overlie the lateral malleolus (a bony prominence at the ankle) instead of the calf. These women also had less subcutaneous fat, so that the tubing pressed directly onto the skin and underneath it, the bone. We therefore identified a high-risk group: women less then 161cm in height, with a BMI <23.

We sought to reduce the risk of pressure sores caused by ICDs, in these patients in particular. As our audit revealed an ongoing problem, not just an exceptionally rare incident, we informed the theatre management, acquisition department and medical and nursing teams about this identified problem. Alternative pumps were sought to provide a solution for the pressure sore problems as well as protection against venous thromboembolism.

Strategies for quality improvement/change

We wanted to trial a different device to see if pressure areas were avoidable. We therefore examined alternative ICDs in which the entry site for the inflation tube is external to the inflation pocket. The surface in contact with the leg is completely flat. The theatre usage committee approved the trial of the new ICD and the company agreed to provide the plastic surgery department with two pumps and 20 sets of leg cuffs to trial, free of charge.

A further prospective audit was carried out on the next 20 consecutive patients undergoing free flap breast reconstruction, in the same manner as the previously collected data using the alternative ICD. We found that all patients were free of redness and paraesthesia, and 19 out of 20 patients had no pain or discomfort in their legs either postoperatively or 48 hours later. One patient complained of mild discomfort in one leg post operatively but this had resolved within 8 hours of removing the ICD. There had been difficulties encountered during her surgery, extending the length of her operation to 17 hours.

There were no clinically detected bleeding complications nor deep vein thromboses in either the pre or post-intervention audits. The cuffs were easy to apply and the pumps easy to program and transport. The alternative pumps were lighter and smaller than the previously used pumps. The theatre and ward nursing staff voiced no concerns or difficulties with the use of the alternative pumps. The use of the new devices was justified as the risk of pressure areas was lower. The change to using the new device was straightforward and effective.

Our study concludes that when surgical time is over 8 hours and patients have BMI<23 and are <160cm in height, we avoided post operative pressure areas by using an ICD in which the inflation tubing was external to the inflation pocket. The inner surface of the cuff, which is adjacent to the patient's leg, is soft and flat and comfortable for the patient.

Discussion points

ICDs have been shown to be safe and effective in preventing venous thromboembolism in the majority of patients (Handoll et al 2002). However, reduced compliance has been noted due to machine noise preventing sleep (32/846: 4%) and ankle discomfort (14/846: 2%) (Pitto and Young 2008, Handoll et al 2002), although pressure sores caused by ICDs have not been reported previously. It would appear from our small prospective audits, that the alternative sequential compression device would be favoured over the ICD device used previously in a small group of patients, namely: women less than 160cm in height with a BMI of less than 23, and undergoing operations lasting longer than eight hours. The original ICD supplier has been approached and advised of these potential problems, and is currently investigating the situation. We will be working with the company to alter the advice leaflet, so that this potential problem is highlighted and any harm to patients avoided. It should be stressed that this device is safe and its use not associated with any problems in the majority of patients.

References

Comerota AJ, Chouhan V, Harada RN et al 1997 The fibrinolytic effects of intermittent pneumatic compression: mechanism of enhanced fibrinolysis Annals of Surgery 226 (3) 306-14

Eppsteiner RW, Shin JJ, Johnson J, van Dam RM 2010 Mechanical compression versus subcutaneous heparin therapy in postoperative and post-trauma patients: a systematic review and meta-analysis World Journal of Surgery 34 (1) 10-19

Freedman KB, Brookenthal KR, Fitzgerald RH Jr, Williams S, Lonner JH 2000 A meta-analysis of thromboembolic prophylaxis following elective total hip arthroplasty Journal of Bone and Joint Surgery 82A (7) 929-38

Handoll HH, Farrar MJ, McBirnie J et al 2002 Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures Cochrane Database Systematic Reviews (4):CD000305

Pitto RP, Young S 2008 Foot pumps without graduated compression stockings for prevention of deep-vein thrombosis in total joint replacement: efficacy, safety and patient compliance. A comparative, prospective clinical trial International Orthopaedics 32(3) 331-36

Urbankova J, Quiroz R, Kucher N, Goldhaber SZ 2005 Intermittent pneumatic compression and deep vein thrombosis prevention. A meta-analysis in postoperative patients Thrombosis Haemostasis 94 (6) 1181-185

Joanna Skillman

BM, BCh, FRCS (Plast)

SpR Plastic Surgery, University Hospital Coventry and Warwickshire NHS Trust

Sunil Thomas

MS, FRCS (Plast)

Consultant Plastic Surgeon, Selly Oak Hospital, University Hospital Birmingham NHS Foundation Trust

No competing interests declared

Correspondence address:Joanna Skillman, Plastic Surgery, University Hospital Coventry and Warwickshire NHS Trust, Coventry, CV2 2DX. Email: joskillman@doctors.org.uk

Provenance and Peer review: Unsolicited contribution; Peer reviewed; Accepted for publication September 2011.
Gale Copyright: Copyright 2011 Gale, Cengage Learning. All rights reserved.